In a wireless communication system, for example a wireless local area network (WLAN) environment of the institute of electrical and electronics engineers (IEEE) 802.11, a data frame is transferred via an access point (AP) or directly by a peer-to-peer method. However, according to a general transfer method that uplinks and downlinks the data frame with respect to the AP, other devices present in the network, such as stations, have to contend to obtain a channel. Accordingly, a throughput for data transfer may be reduced.
To solve such a limit, the data frame may be directly transferred between stations without passing through the AP through a direct link setup (DLS) mode between the stations, such that a channel use efficiency may be at least doubled. However, even when the DLS mode is used, the throughput of the wireless network may be reduced when a channel state is deteriorated by multiple paths, attenuation, interference and the like. Also, in a case requiring a quality of service (QoS), such as multimedia streaming, a demanded QoS may not be met.
In particular, the foregoing limits may become prominent in the WLAN, such as a 60 gigahertz (GHz) band that is currently standardized and uses millimeter waves. Millimeter wave communication may easily transfer data of several gigabits per second (Gbps) without high modulation, using a wide band such as a 2 GHz band. However, the millimeter wave communication may cause considerable loss of power due to characteristics of high frequency waves having a high degree of straightness. To overcome the loss of power, obtaining a high antenna gain by collecting power in a particular direction is recommended, rather than all directions using a directional antenna.
However, when a line-of-sight (LOS) is not secured, signals may be transferred in a reflective manner. In this case, a signal transfer distance is increased, thereby increasing an attenuation loss. Consequently, loss by the reflection may be added. Furthermore, when a person interrupts the LOS, a penetration loss becomes almost 20 decibels (dB) or more. Since an interior door or wall usually causes a greater loss by interruption, it is difficult for signals to reach a destination.
As aforementioned, to overcome limits that may occur even with use of the DLS mode and the directional antenna, there is a need for a method enabling relay of a frame through another station other than the AP in the wireless network.